Aspirating cartridge syringe with gas actuation



Aug.l12, 1969 l R. @BLACK 3,460,534

lSPIIRATING CARTRIDGE SYRINGE MIIITH GAS ACTUATION Filed Nov. 25. 1966INVENTOR.

United States Patent Otce 3,460,534 Patented Aug. 12, 1969 3,460,534ASPIRATING CARTRIDGE SYRINGE WITH GAS ACTUATION Robert E. Black, 2925Denver St., Corpus Christi, Tex. 78404 Continuation-impart ofapplication Ser. No. 559,703, Apr. 28, 1966. This application Nov. 25,1966, Ser. No. 597,077 The portion of the term of the patent subsequentto Mar. 18, 1986, has been disclaimed Int. Cl. A61m 5/18, 5/22 U.S. Cl.128--218 1 Claim ABSTRACT OF THE DISCLOSURE The present application is acontinuation-in-part of my prior application Ser. No. 559,703, tiledApr. 28, 1966-, now abandoned.

This invention relates to hypodermic syringes and the invention isparticularly concerned with a syringe of the type adapted to receive apiston-cylinder cartridge and in which provision is made for alternativerelative advancement and withdrawal of the piston with respect to thecylinder, in order to provide alternatively for aspiration through theneedle into the cartridge and for expulsion of the material to beinjected from the cartridge through the needle.

In equipment of the kind mentioned, the piston is ordinarily formed of asoft material, such as rubber, and is advanced into the cylinder by anactuating element or plunger -for the purpose of making the injection.Moreover, means are provided for fastening the piston to the actuatingelement so that when the actuating element is Withdrawn, the piston isalso retracted. Retraction of the piston eiects the aspiration, and witha cartridge cylinder formed of transparent material, the aspiration ofblood or of liquid through the needle into the cartridge cylinder mayreadily be observed.

Various forms of mechanism have been proposed for interconnecting thepiston and the actuating element, certain of such devices comprisingbarbs, or being of harpoonlike shape, adapted to penetrate the rubber ofthe piston and thereby interlock with the rubber to provide forwithdrawal of the piston from the cylinder and thus effect aspiration.The use of corkscrew shaped, or twisted elements, has also beenproposed.

Various of these prior devices are usable but are subject to certaindifficulties and disadvantages including the fact that the arrangementthereof commonly results in some appreciable stretching or distortion ofthe rubber of the piston upon the withdrawal motion of the actuatingelement, so that the withdrawal motion of the piston lags -behind thewithdrawal motion of the actuating element. Moreover, the aspiratingaction tends to become indefinite when the Withdrawal motion of thepiston lags behind the withdrawal motion of the actuating element. Withcertain of the prior arrangements employing barbs or harpoon typestructures, the rubber of the piston tends to Ibecome distorted in amanner impairing the seal or altering the iit of the piston in thecylinder.

Still further, with certain of the prior arrangements ernploying curvedor corkscrew type of piston retracting projections, it is necessary torelatively rotate the cartridge and the actuating plunger in order tocause the corkscrew projections to enter the rubber of the piston. Sincetriction alone restrains relative turning of the piston and cylinder ofthe cartridge the manual rotation. of the cartridge cylinder is notalways fully communicated to the piston, with the result that theconnection between the actuating plunger and the piston may be impaired.

The present invention provides a novel piston retractor arrangementconstructed to overcome various of the ditliculties encountered withprior arrangements. Thus, with the arrangement of the present inventionthe connection between the actuating plunger and the piston provides asecure connection as a result of a rm frictional grip, which does notrequire relative rotation of the cartridge piston and the plunger hooksor barbs, and which, moreover, ensures that the piston will closelyfollow the motion of the actuating plunger, without any appreciable lag.Also, the arrangement of the invention substantially eliminates anydistortion of the rubber of the piston to an extent impairing the sealor fit of the piston in the cylinder.

How the foregoing objects and advantages are obtained, together withothers which will occur to those skilled in the art will be clear fromthe fololwing description referring to the accompanying drawing inwhich:

FIGURE 1 is a longitudinal sectional View through a hypodermic syringeembodying the improvements of the present invention;

FIGURE 2 is a fragmentary view of the left end portion of the instrumentof FIGURE 1 and illustrating the insertion of a hypodermie needle;

FIGURE 3 is a longitudinal sectional view similar to FIGURE 1 butillustrating certain of the parts in a different position;

FIGURE 4 is a transverse sectional view taken as indicated by thesection line 4 4 on FIGURE 3; and

FIGURE 5 is a longitudinal sectional view of the righthand end portionof the instrument, with certain parts in still another position, ascompared with FIGURES 1 and 3.

In connection with the embodiment illustrated in the drawing, it is rstto be noted that the instrument there shown is of the general typedisclosed in my copending application above identified, i.e., theinstrument is of the type incorporating a power actuating systemoperating by gas pressure. Moreover the instrument illustrated in thedrawing of the present application is similar to the instrument shown inFIGURES 11 to 15 of my copending application referred to.

As seen particulary in FIGURES 1 and 2, the instrument includes tubularmembers 6 and 7 having telescopically interfitting parts 8 and 9,preferably with a bayonet type connection of the kind referred to in theabove mentioned copending application.

The tubular member 6 has a cylindrical chamber therein adapted toreceive a catridge comprising a cylinder 10 having a free piston 11 inone end and having a puncturable diaphragm 12 in the other end.

The left end of the member 6 is provided with a threaded cap 13 adaptedto receive a cup 14, the cup being shiftable within the member 13 andbeing normally urged toward the right as viewed in FIGURES 1 and 3 bymeans of a coil spring 15, the range of movement of the cup being shownby comparison of FIGURE 1 and 3 The tubular member 7 of the assembly isadapted to receive the piston 16 having a sealing ring 17 toward itsrighthand end. Moreover, the righthand end of the tubular member 7 has acap 18, this cap being adapted to contain a charge of pressure fluid forthe purpose of actuating the piston 16 when the instrument is in use. Aplug 19, formed of material which may be penetrated by a charging needleis provided at the extremity of the cap 13, so that when needed,additional pressure fluid may be introduced into the pressure chamber.

When the pressure chamber is charged, the pressure thereof will actagainst the righthand end of the plunger 16, thereby urging the plunger16 to the left.

The lefthanrd end of the plunger 16 carries an abutment element 20through which motion of the plunger to the left is transmitted to therubber piston 11 of the cartridge placed in the syringe, and in this waythe pressure of the Huid in the cap 18 serves to advance the piston 11in the cylinder 1G in order to expel the material in the cylinder andthus effect injection by the syringe.

The motion of the plunger 16 is adapted to be controlled by a brake 21(see also FIGURES 3 and 5) of semi-cylindrical shape positioned on theunder-side of the plunger 16 and mounted in a bore provided in acylindrical part 22 formed at the lower side of the tubular member 7.This brake shoe 21 is urged upwardly against the lower surface of thepiston '16 by means of compression spring 23 which reacts against anadjustable screw plug 24.

The brake shoe 21 is controlled by a brake rod 25 which extends upwardlythrough an axial slot formed in the plunger 16, the upper or free end ofthe brake rod 25 being exposed outside of the tubular member 7 inposition to be contacted by the operating element or lever 26. When thelever 26 is pressed downwardly, for instance as illustrated in FIGURE 5,the brake rod 25 is depressed, thereby displacing the brake shoe 21 fromthe lower surface of the piston 16, and thus releasing the plunger formovement toward the left when viewed as in FIG- URES l, 3 and 5, underthe influence of the pressure tluid behind the plunger.

Lever 2o is mounted by means of a pivot 27 the ends of which aresupported in apertured lugs 28-28' projecting from the tubular member 7.

Lever 26 is further provided with an actuating finger 29 which isreceived in a socket formed at the upper side f a push rod 3@ which ismounted for reciprocation or shifting movement lengthwise of theinstrument within a groove or slot formed in the inner surface of thetubular member 7. Preferably the push rod 36 and the slot in which itworks are so shaped as to restrain outward dislodgement of the pushrod,while permitting its longitudinal motion.

The push rod 3? is positioned so that its lefthand end will engage therighthand end of the cylinder 1li of the cartridge inserted into thetubular member 6. The purpose of this arrangement will be describedshortly below.

Attention is now called to the lefthand end :of FIG- URE 2 Where thereis shown a hypodermic needle 31 mounted by means of a cap 32, with theinner end of the needle 31 penetrating the diaphragm 12 at the left endof the cartridge. Attention is also called to the fact that the tubularmember 6 is provided with an elongated aperture 33 in a sidewall thereofthrough which the cartridge is visible. With the cylinder of thecartridge formed of transparent material, as is customary, the aperture33 in the tubular member 6 serves, in effect, as a window through whichthe interior of the cartridge may be observed.

Attention is now called to the fact that the abutment Ztl at the end ofthe plunger 16 is secured to the plunger by a threaded shank 34 receivedin a complementarily threaded aperture in the end of the plunger 16.

According to the present invention, a novel arrangement of elements isprovided for establishing interengagement between the abutment member 2@and the rubber piston 11. In the embodiment illustrated in the drawings,this purpose is served by two pins 35 projecting from the element 2t),the postions of these pins appearing 4 clearly in FIGURE 4, in which,fo-r the sake of illustration, the rubber piston 11 has been omitted.

When the instrument is prepared for use, the cartridge comprising thecharged cylinder 1@ with the free piston 11 therein is placed into theopen righthand end of the tubular part 6 prior to assembly of thetubular parts 6 and 7. The two tubular parts of the instrument are thenbrought together and assembled by telescoping the portions S and 9 andthe parts are fastened together by rotation of the bayonet joint abovementioned. The telescoping movement of the parts 6 and '7 will cause thepins 35 to enter the rubber of the piston 11, and in this condition ofassembly, the parts appear as they are shown in FIGURE l.

The hypodermic needle 31 is then inserted and fastened in place by meansof the screw cap 32, and during this insertion the inner end of theneedle penetrates the diaphragm 12, and the instrument is now ready foruse.

When used, the needle is of course inserted to or into the target areaof the tissue, and in doing this, the instrument may be handled byemploying the pen grasp, with the instrument lying in the tirst andsecond fingers of the hand and with a linger or thumb overlying theactuating lever 26, all in the manner fully described in the copendingapplication above referred to. The operating element or lever 26 maythen be actuated, for instance by the thumb, or within the grasp of thehand, without requiring shift in position of the hand. The initialmotion of the lever 26, for instance the motion from the position shownin FIGURE 1 to the position shown in FIGURE 3 will shift the push rod 30to the left and thereby shift the cylinder 10 of the cartridge to theleft, for instance from the position shown in FIGURE 1 to the positionshown in FIGURE 3, the spring 15 being compressed during this action.Moreover, at this time, because of the penetration of the pins 35 in therubber of the free piston 11, a firm frictional grip is establishedbetween the piston itself and the element 20, in consequence of whichthe piston does not follow the cylinder but is retained in substantiallyits initial position. The action just described results in reduction ofpressure within the cartridge and, in consequence an aspiration effectthrough the needle 31 into the left end of the cartridge. In the eventthat the needle has been positioned in a blood vessel, for instance in aVein, this aspirating effect will draw into the cartridge a smallglobule of blood, as indicated at B in FIGURE 3. This globule is visiblethrough the transparent cylinder 1t) and through the Window 33 in thetubular member 6, and thereby the operator is warned of the positioningof the needle within a blood vessel.

The instrument may be employed for various different purposes, and forsome of such purposes it is desired that the needle be positioned withina blood vessel and for others of which it is not desired that the needlebe positioned within a blood vessel. In the former case, the aspirationof the globule of blood will at once advise the operator that the needleis properly positioned to proceed with the injection. In the lattercase, the aspiration of the globule of blood will advise the operatorthat the needle is not properly positioned, and the operator may thenrelease the lever 26 and thereafter reposition the needle so as tolocate it in the tissue exteriorly of the blood vessels prior to makingthe injection.

In the event of either type of use, after the operator has determinedthat the needle is positioned as intended, the operator may then furtherdepress the lever 26, in consequence of which the brake rod 25 isengaged and displaced, thus releasing the braking action of the brakeshoe 21 against the piston 16, so that the piston will be moved underthe inuence of the fluid pressure behind it, thereby advancing the freepiston 11 into the cylinder 10 of the cartridge and thus injecting thecharge of the cartridge through the needle into the target area.

If desired the operator may use the instrument shown in the drawing formaking several injections from one cartridge, the quantity of materialinjected being readily controlled by release and reengagement of thebrake shoe 21. The instrument will always automatically aspirate beforeeach injection. A spent cartridge may readily be removed by separationof the two tubular parts of the instrument 6 and 7, thereby permittingremoval of the spent cartridge from the open end of the tubular member6. The free piston 11 of a spent cartridge may also readily be removedfrom the pins 35, such removal not requiring a twisting motion, as withcertain prior devices.

The arrangement of the pins 35, including the fact that several straightpins of relatively small diameter are preferably employed makes possiblethe penetration of the pins into the rubber of the free piston 11without any extensive distortion of the rubber of the piston, such aswould impair the tit or seal of the piston 11 within the cylinderMoreover, the employment of a plurality of the piston penetrating pins,especially with two or of three siich pins, produces an interconnectionbetween the free piston itself and the actuating elements and 16 whichvirtually eliminates lag between the motion of the actuating elementsand the motion of the free piston, this being of importance, in theoperation of an aspirating type of hypodermic syringe, as is mentionedhereinabove.

It will be noted from the drawing that the two pins of the embodimentillustrated are located at some appreciable distance from thecircumference of the piston. I have found that it is preferred, whenemploying two pins, to position the pins not more than about 1/2 of theradius of the piston from the center thereof. For instance with atypical piston of 1A inch diameter, the pins are preferably not morethan about 1/{16 inch from the center, for instance at about Xg of aninch. While I presently prefer the employment of two pins as abovedescribed, three pins also serve the purpose quite well and may besimilarly positioned with reference to the center of the piston. Asingle straight pin may also be utilized, in which event the pin ispreferably placed at the center of the piston and also is preferably ofsomewhat larger diameter than when employing two or three pins.

In a typical case where the free piston of the cartridge is .25 inchdiameter, and where two or more pins are employed the pins are desirablyof about 0.024 inch in diameter. Where a single pin is used its diametermay desirably be about 0.030 inch.

After use of the instrument, during which the plunger or actuatingelement 16 will be moved through a substantial stroke toward the left asviewed in the drawing, the pressure fluid in the instrument may berecycled by forcing the plunger 16 into the tubular member 7, i.e.,toward the right as viewed in the drawing. This will cause the gas to berecycled to liquid phase in the chamber just ahead of the cap 18, sothat the instrument becomes ready for another use, after the insertionof another cartridge into the tubular member 6.

The means or mechanism employed for the purpose of forcing the plunger16 back into the tubular member 7 forms no part of the present inventionper se, but it may be here noted that a mechanism for this purpose mayconform with that disclosed in FIGURE 10 of my copending applicationabove identied.

For use as an actuating fluid or propellant, certain Freou gases may beused, such as monochlorodifluoromethane, a source of which is known tothe trade as Freon 22 marketed by E. I. du Pont de Nemours & Co. Thismaterial, introduced initially in liquid form will establish an internalpressure within the cartridge, i.e., behind the free piston 11, whichpressure will be approximately p.s.i. at 76 F. Other fluids which may beemployed as propellants are certain Genetrons (General Chemical Div.)and Ucons (Carbide and Carbon Chemicals Co.). Another specific exampleof an appropriate material is dichlorodifluoromethane which is availableunder the trade name Freo-n 12 (E. I. du Pont de Nemours & Co.).

Various of these fiuorocarbons are colorless, almost odorles,nonflammable and virtually non-toxic so they are highly suitable to usein the medical field without hazard.

As with the instrument shown in FIGURES l1 to 15 of my copendingapplication above identified, the instrument of the present applicationprovides for effecting aspiration in advance of making an injection.Indeed this instrument assures that aspiration will be effected inadvance of injection. lMoreover with the arrangement of the presentinvention the aspiration is effected with definiteness and assurance,especially since the straight pin arrangement greatly diminishes the lagbetween the aspirating motion of the piston and the motion of theactuating mechanism.

The instrument of the invention is capable of use with cartridges of atype now widely available.

I claim:

1. A hypodermic syringe having a chamber for receiving a piston andcylinder type cartridge having a transparent wall and containingmaterial to be injected, the syringe chamber providing for visualobservation of the cartridge received therein and having means formounting a hypodermic needle in position to penetrate the cartridge, andmechanism providing alternatively for relative advancement andwithdrawal of the piston with respect to the cylinder of the cartridgereceived in the syringe chamber, said mechanism comprising an actuatingelement engageable with the piston and movable axially of the cartridgecylinder for advancing the piston into the cylinder and thus effectexpulsion of the material to be injected from the cartridge through theneedle, a piston penetrating pin connected with the piston actuatingelement and projecting from the actuating element axially of thecartridge cylinder, said pin `being straight, free of lateralprojections and thus of substantially uniform diameter and providing africtional grip with the piston effective to retract the piston withrespect to the cylinder, means for advancing the cartridge cylinderwhile retaining the piston actuating element as against advancement withthe cylinder to thereby effect relative withdrawal of the piston withrespect tothe cylinder under the action of said frictional grip andthereby effect aspiration through the needle into the cartridge, and amanually operable control member movable in one direction tosequentially effect operation of said means for advancing the cartridgecylinder and then effect operation of said actuating element to move thepiston in the cartridge for expulsion of the material to be injected.

References Cited UNITED STATES PATENTS 1,971,687 8/1934 Kratz l28-2l82,672,142 3/1954 Melton 178-218 3,224,445 12/ 1965 Melott 12S-218FOREIGN PATENTS 776,968 11/1934 France.

RICHARD A. GAUDET, Primary Examiner MARTIN F. MAJESTIC, AssistantExaminer

